Answer:
Promoter, in chemistry, substance added to a solid catalyst to improve its performance in a chemical reaction. By itself the promoter has little or no catalytic effect. Some promoters interact with active components of catalysts and thereby alter their chemical effect on the catalyzed substance.
Explanation:
Answer:
D
Explanation:
Friction plays an important part in many everyday processes. For instance, when two objects rub together, friction causes some of the energy of motion to be converted into heat.
Answer:
d. oxygen is a pure substance and rocks are mixtures
Answer:
The ratio, ![\frac{[HCO_{3}^{-}]}{[H_{2}CO_{3}]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BHCO_%7B3%7D%5E%7B-%7D%5D%7D%7B%5BH_%7B2%7DCO_%7B3%7D%5D%7D)
, is 10.7
Explanation:
is an weak acid and 
is it's conjugate base.
So, according to Henderson-Hasselbalch equation, pH of this buffer system can be represented as-
![pH=pK_{a}(H_{2}CO_{3})+log(\frac{[HCO_{3}^{-}]}{[H_{2}CO_{3}]})](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28H_%7B2%7DCO_%7B3%7D%29%2Blog%28%5Cfrac%7B%5BHCO_%7B3%7D%5E%7B-%7D%5D%7D%7B%5BH_%7B2%7DCO_%7B3%7D%5D%7D%29)
Here pH=7.40, 
=6.37
So, ![7.40=6.37+log(\frac{[HCO_{3}^{-}]}{[H_{2}CO_{3}]})](https://tex.z-dn.net/?f=7.40%3D6.37%2Blog%28%5Cfrac%7B%5BHCO_%7B3%7D%5E%7B-%7D%5D%7D%7B%5BH_%7B2%7DCO_%7B3%7D%5D%7D%29)
or, ![\frac{[HCO_{3}^{-}]}{[H_{2}CO_{3}]}=10.7](https://tex.z-dn.net/?f=%5Cfrac%7B%5BHCO_%7B3%7D%5E%7B-%7D%5D%7D%7B%5BH_%7B2%7DCO_%7B3%7D%5D%7D%3D10.7)
So the ratio, , is 10.7
